1. Field of the Invention
The present invention pertains to transistor devices and particularly to a method of making a plurality of single duffused transistor devices on a single semiconductor wafer.
2. Description of the Prior Art
At least one form of prior art involves diffusing a semiconductor wafer to form either a PNP or an NPN structure and then scribing the wafer with a glass cutter to produce a plurality of transistor chips. A problem with such a prior art method is the inability to accurately categorize the electrical characteristics of the transistors until they have been separated into chips. The present invention provides a means for isolating and passivating individual transistors while they are still an integral part of the starting wafer, thereby permitting accurate electrical testing of a plurality of transistors prior to separation of the starting wafer into discrete transistor chips.